U.S. patent number 10,804,484 [Application Number 16/032,102] was granted by the patent office on 2020-10-13 for lighting panel and method of fabricating the same, lighting module, lighting device, and lighting system.
This patent grant is currently assigned to LG Display Co., Ltd.. The grantee listed for this patent is LG Display Co., Ltd.. Invention is credited to Nam-Kook Kim, Tae-Ok Kim, Jung-Eun Lee.
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United States Patent |
10,804,484 |
Kim , et al. |
October 13, 2020 |
Lighting panel and method of fabricating the same, lighting module,
lighting device, and lighting system
Abstract
A lighting panel and method of fabricating the same, lighting
module, lighting panel, and lighting system are provided. The
lighting panel includes a material layer on a substrate; an
auxiliary electrode embedded in the material layer; a first
electrode on the material layer and electrically connected to the
auxiliary electrode; an organic light-emitting layer and a second
electrode in an emission portion where the first electrode is
provided; and an encapsulation member in the emission portion of
the substrate.
Inventors: |
Kim; Nam-Kook (Paju-si,
KR), Lee; Jung-Eun (Goyang-si, KR), Kim;
Tae-Ok (Ansan-si, KR) |
Applicant: |
Name |
City |
State |
Country |
Type |
LG Display Co., Ltd. |
Seoul |
N/A |
KR |
|
|
Assignee: |
LG Display Co., Ltd. (Seoul,
KR)
|
Family
ID: |
1000005114798 |
Appl.
No.: |
16/032,102 |
Filed: |
July 11, 2018 |
Prior Publication Data
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|
|
Document
Identifier |
Publication Date |
|
US 20190019978 A1 |
Jan 17, 2019 |
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Foreign Application Priority Data
|
|
|
|
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Jul 11, 2017 [KR] |
|
|
10-2017-0088046 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L
51/5253 (20130101); H01L 51/0097 (20130101); H01L
51/56 (20130101); H01L 51/5268 (20130101); H01L
51/5212 (20130101); H01L 2251/5361 (20130101); H01L
2251/5392 (20130101); H01L 51/5203 (20130101); H01L
51/5275 (20130101); H01L 2251/5338 (20130101) |
Current International
Class: |
H01L
51/52 (20060101); H01L 51/00 (20060101); H01L
51/56 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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EP |
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2 698 836 |
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EP |
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2-66870 |
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Mar 1990 |
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JP |
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2013521563 |
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Jun 2013 |
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JP |
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2014096334 |
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May 2014 |
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JP |
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2015535138 |
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Dec 2015 |
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JP |
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2016509359 |
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Mar 2016 |
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JP |
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10-2003-0077461 |
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Oct 2003 |
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KR |
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10-2014-0116034 |
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Oct 2014 |
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KR |
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10-2015-0002218 |
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10-2015-0095408 |
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KR |
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10-2016-0144313 |
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Dec 2016 |
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KR |
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201436329 |
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Sep 2014 |
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TW |
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2013/153700 |
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Oct 2013 |
|
WO |
|
Other References
Office Action dated Apr. 23, 2019 with English translation issued
in the corresponding Japanese Patent Application No. 2018-131215, 9
Pages. cited by applicant .
Search Report dated Nov. 30, 2018 issued in the corresponding
European Patent Application No. 18182694.2, pp. 1-10. cited by
applicant .
Office Action dated Jun. 12, 2019 issued in the corresponding
Taiwanese Patent Application No. 107123864 (21 pages). cited by
applicant.
|
Primary Examiner: Mandala; Michelle
Attorney, Agent or Firm: Polsinelli PC
Claims
What is claimed is:
1. A lighting panel using an organic light-emitting diode,
comprising: a material layer disposed on a substrate; an auxiliary
electrode embedded in the material layer; a first electrode
disposed on the material layer and electrically connected to the
auxiliary electrode; an organic light-emitting layer and a second
electrode disposed at an emission portion where the first electrode
is located; an encapsulation member disposed on the emission
portion of the lighting panel; a short reduction pattern indisposed
at the first electrode and surrounding an emission area of each
pixel of the lighting panel, and a first passivation layer between
the first electrode and the organic light-emitting layer, wherein
the first passivation layer covers the short reduction pattern and
exposes the first electrode, wherein a distance between the first
electrode exposed by the first passivation layer and the second
electrode is smaller than a distance between the short reduction
pattern covered by the first passivation layer and the second
electrode, wherein the material layer includes a buffer layer,
wherein the material layer further includes an inner light
extraction layer between the substrate and the buffer layer,
wherein the auxiliary electrode is embedded up to a thickness of
the buffer layer, and is further embedded up to a thickness of the
inner light extraction layer or a part of the thickness of the
inner light extraction layer, and wherein an upper surface of the
auxiliary electrode is flush with an upper surface of the buffer
layer such that the first electrode has a planarized surface.
2. The lighting panel of claim 1, wherein an upper surface of the
material layer is flush with or disposed higher than an upper
surface of the auxiliary electrode.
3. The lighting panel of claim 1, wherein a position of the first
electrode in contact with the auxiliary electrode is lower than an
upper surface of the material layer.
4. A lighting panel using an organic light-emitting diode,
comprising: a material layer disposed on a substrate; an auxiliary
electrode embedded in the material layer; a first electrode
disposed on the material layer and electrically connected to the
auxiliary electrode; an organic light-emitting layer and a second
electrode disposed at an emission portion where the first electrode
is located; an encapsulation member disposed on the emission
portion of the lighting panel; a short reduction pattern indisposed
at the first electrode and surrounding an emission area of each
pixel of the lighting panel, and a first passivation layer between
the first electrode and the organic light-emitting layer, wherein
the first passivation layer covers the short reduction pattern and
exposes the first electrode, wherein a distance between the first
electrode exposed by the first passivation layer and the second
electrode is smaller than a distance between the short reduction
pattern covered by the first passivation layer and the second
electrode, wherein the material layer includes a buffer layer,
wherein the material layer further includes an inner light
extraction layer between the substrate and the buffer layer,
wherein the auxiliary electrode is embedded up to a part of a
thickness of the buffer layer, and is further embedded up to a
thickness of the inner light extraction layer or a part of the
thickness of the inner light extraction layer, and wherein a
portion corresponding to a rest of the thickness of the buffer
layer other than the part is filled with the first electrode such
that the first electrode has a planarized surface.
5. The lighting panel of claim 1, wherein the auxiliary electrode
does not protrude above the buffer layer.
6. The lighting panel of claim 1, wherein the auxiliary electrode
has a reversed taper in cross-section such that an upper part of
the auxiliary electrode has a wider width than a lower part of the
auxiliary electrode.
7. The lighting panel of claim 1, wherein the first passivation
layer further covers the auxiliary electrode and the first
electrode thereon.
8. A lighting panel using an organic light-emitting diode,
comprising: a buffer layer disposed on a substrate; an auxiliary
electrode embedded in the buffer layer and arranged in a mesh shape
at an emission portion of the lighting panel; a first electrode
disposed on the buffer layer and electrically connected to the
auxiliary electrode for applying uniform current to the first
electrode; an organic light-emitting layer on the first electrode;
a second electrode disposed on the organic light-emitting layer; a
short reduction pattern disposed at the first electrode and
surrounding an emission area of each pixel of the lighting panel,
and a first passivation layer between the first electrode and the
organic light-emitting layer, wherein the first passivation layer
covers the short reduction pattern and exposes the first electrode,
wherein a distance between the first electrode exposed by the first
passivation layer and the second electrode is smaller than a
distance between the short reduction pattern covered by the first
passivation layer and the second electrode, wherein an inner light
extraction layer is further disposed between the substrate and the
buffer layer, wherein the auxiliary electrode is embedded up to a
thickness of the buffer layer, and is further embedded up to a
thickness of the inner light extraction layer or a part of the
thickness of the inner light extraction layer, and wherein an upper
surface of the auxiliary electrode is flush with an upper surface
of the buffer layer such that the first electrode has a planarized
surface.
9. The lighting panel of claim 8, wherein the auxiliary electrode
has a reversed taper in cross-section such that an upper part of
the auxiliary electrode has a wider width than a lower part of the
auxiliary electrode.
10. The lighting panel of claim 8, wherein the first passivation
layer further covers the auxiliary electrode and the first
electrode thereon.
11. The lighting panel of claim 1, wherein the short reduction
pattern has first, second, third, fourth and fifth parts, the
first, second, third, fourth and fifth parts are sequentially and
continuously connected to each other and the first and fifth parts
are separated from each other, and wherein the first, third and
fifth parts extend along a first direction, and the second and
fourth parts extend along a second direction crossing the first
direction, and wherein the first part is disposed between the third
and fifth parts.
12. The lighting panel of claim 8, wherein the short reduction
pattern has first, second, third, fourth and fifth parts, the
first, second, third, fourth and fifth parts are sequentially and
continuously connected to each other and the first and fifth parts
are separated from each other, and wherein the first, third and
fifth parts extend along a first direction, and the second and
fourth parts extend along a second direction crossing the first
direction, and wherein the first part is disposed between the third
and fifth parts.
13. The lighting panel of claim 1, wherein a width of the short
reduction pattern is smaller than a width of the first
electrode.
14. The lighting panel of claim 8, wherein a width of the short
reduction pattern is smaller than a width of the first electrode.
Description
CROSS-REFERENCE TO RELATED APPLICATION
The present application claims priority from and the benefit under
35 U.S.C. .sctn. 119(a) of Korean Patent Application No.
10-2017-0088046 filed on Jul. 11, 2017, which is hereby
incorporated by reference in its entirety.
BACKGROUND
Field of the Disclosure
The present disclosure relates to a lighting panel and a method of
fabricating the same, lighting module, lighting panel, and lighting
system, and more particularly, to a lighting panel using an organic
light-emitting diode and a method of fabricating the same, lighting
module, lighting panel, and lighting system.
Description of the Background
Fluorescent lamps or incandescent lamps are mainly used as current
lighting devices. The incandescent lamps have good color rendering
index (CRI) and very low energy efficiency. The fluorescent lamps
have good energy efficiency. However, the fluorescent lamps have
low CRI and also have an environmental problem because they contain
mercury.
The color rendering index is an index representing a degree of
color reproduction. The color rendering index is an index showing
how similar feelings of colors of an object illuminated by light
sources are by comparing a case where the object is illuminated by
a specific light source and a case where the object is illuminated
by a reference light source. For example, the CRI of sunlight is
100.
In order to solve the problem of this conventional lighting device,
a light-emitting diode (LED) has recently been proposed as a
lighting device. The light-emitting diode is formed of an inorganic
light-emitting material. Its luminous efficiency is the highest in
the blue wavelength range, and the luminous efficiency is lowered
toward the red wavelength range and the green wavelength range
having the highest visibility. Therefore, when white light is
emitted by combining a red light-emitting diode, a green
light-emitting diode, and a blue light-emitting diode, there is a
problem that the luminous efficiency can be lowered.
As an alternative, a lighting panel using an organic light-emitting
diode (OLED) has been developed. In a lighting panel using the
conventional organic light-emitting device, an anode electrode of
ITO is formed on a glass substrate. Then, an organic light-emitting
layer and a cathode electrode are formed, and a passivation layer
and a lamination film of an encapsulation member are adhered
thereon.
In the lighting panel using an organic light-emitting diode, an
auxiliary electrode is formed for uniform brightness of the
lighting panel emitting planar light. At this time, after
laminating the encapsulation member, the passivation layer and the
cathode can be cracked due to a high taper of the auxiliary
electrode.
FIG. 1 is a picture showing a taper of an auxiliary electrode and a
stack structure thereon in the related art.
At this time, FIG. 1 shows a taper of an auxiliary electrode
including a double layer of Mo/Al and a stack structure thereon as
an example.
Referring to FIG. 1, the auxiliary electrode including a double
layer of Mo/Al has a high taper of 70 degrees or more, for example,
of 80 degrees.
At this time, as the taper of the auxiliary electrode gets higher,
there is high possibility that a crack occurs in a passivation
layer and a cathode on the auxiliary electrode when an
encapsulation member is laminated. More particularly, a step is
formed due to the high taper of the auxiliary electrode, and the
crack occurs in crack weak points by physical pressure when the
encapsulation member is laminated.
This crack may form a penetration path of moisture from an edge of
a panel, and a dark spot may be caused during operation of the
panel, thereby reducing the reliability of the panel.
SUMMARY OF THE DISCLOSURE
Accordingly, the present disclosure is directed to a lighting panel
and a method of fabricating the same, lighting module, lighting
panel, and lighting system that substantially obviates one or more
of the problems due to limitations and disadvantages of the related
art.
An object of the present disclosure is to provide a lighting panel
and a method of fabricating the same, lighting module, lighting
panel, and lighting system of preventing a passivation layer and a
cathode from being cracked due to a step and taper of an auxiliary
electrode.
Additional features and advantages of the present disclosure will
be set forth in the description which follows, and in part will be
apparent from the description, or may be learned by practice of the
present disclosure. The objectives and other advantages of the
present disclosure will be realized and attained by the structure
particularly pointed out in the written description and claims
hereof as well as the appended drawings.
To achieve these and other advantages and in accordance with the
purpose of the present disclosure, as embodied and broadly
described herein, there is provided a lighting panel using an
organic light-emitting diode, comprising: a material layer on a
substrate; an auxiliary electrode embedded in the material layer; a
first electrode on the material layer and electrically connected to
the auxiliary electrode; an organic light-emitting layer and a
second electrode in an emission portion where the first electrode
is provided; and an encapsulation member in the emission portion of
the substrate.
In another aspect, there is provided a lighting module comprising
the lighting panel according to any aspects of the present
disclosure.
In another aspect, there is provided a lighting device comprising
at least one of the lighting panel and the lighting module
according to aspects of the present disclosure.
In another aspect, there is provided a lighting system comprising
at least one of the lighting panel, the lighting module and the
lighting device according to aspects of the present disclosure.
In another aspect, there is provided a method of fabricating a
lighting panel using an organic light-emitting diode includes
forming an inner light extraction layer and/or a buffer layer on a
substrate; forming an auxiliary electrode pattern having a
depressed shape in the inner light extraction layer and/or the
buffer layer by selectively removing the inner light extraction
layer and/or the buffer layer; embedding an auxiliary electrode in
the auxiliary electrode pattern; forming a first electrode on the
buffer layer and electrically connected to the auxiliary electrode;
forming an organic light-emitting layer and a second electrode in
an emission portion where the first electrode is provided; and
forming an encapsulation member in the emission portion of the
substrate.
It is to be understood that both the foregoing general description
and the following detailed description are by example and
explanatory and are intended to provide further explanation of the
present disclosure as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are included to provide a further
understanding of the present disclosure and which are incorporated
in and constitute a part of this specification, illustrate aspects
of the present disclosure and together with the description serve
to explain the principles of the present disclosure. In the
drawings:
FIG. 1 is a picture of showing a taper of an auxiliary electrode
and a stack structure thereon in the related art;
FIG. 2 is a cross-sectional view showing a lighting panel using an
organic light-emitting diode according to a first aspect of the
present disclosure;
FIG. 3 is a plan view schematically showing a lighting panel using
an organic light-emitting diode according to the first aspect of
the present disclosure;
FIG. 4 is a view schematically showing a cross-section of a
lighting panel using an organic light-emitting diode according to
the first aspect taken along the line I-I' in FIG. 3;
FIGS. 5A to 5G are plan views sequentially illustrating a method of
fabricating a lighting panel using an organic light-emitting diode
according to the first aspect of the present disclosure shown in
FIG. 3;
FIGS. 6A to 6G are cross-sectional views sequentially illustrating
a method of fabricating a lighting panel using an organic
light-emitting diode according to the first aspect of the present
disclosure shown in FIG. 4;
FIG. 7 is a view enlarging a part of an emission portion shown in
FIG. 5D;
FIGS. 8A to 8C are cross-sectional views specifically illustrating
a method of forming the auxiliary electrode shown in FIG. 6B;
FIGS. 9A and 9B are cross-sectional views specifically illustrating
another method of forming the auxiliary electrode shown in FIG.
6B;
FIGS. 10A to 10C are cross-sectional views specifically
illustrating another method of forming the auxiliary electrode
shown in FIG. 6B;
FIG. 11 is a plan view schematically showing a lighting panel using
an organic light-emitting diode according to a second aspect of the
present disclosure;
FIG. 12 is a view schematically showing a cross-section of the
lighting panel using an organic light-emitting diode according to
the second aspect of the present disclosure taken the line II-II'
in FIG. 11;
FIG. 13 is a cross-sectional view schematically showing a lighting
panel using an organic light-emitting diode according to a third
aspect of the present disclosure; and
FIG. 14 is a cross-sectional view schematically showing a lighting
panel using an organic light-emitting diode according to a fourth
aspect of the present disclosure.
DETAILED DESCRIPTION OF THE ASPECTS
Hereinafter, a lighting panel using an organic light-emitting diode
and a method of fabricating the same according to exemplary aspects
of the present disclosure will be described with reference to the
accompanying drawings.
Advantages and features of the present disclosure and methods of
accomplishing the same will be clearly understood with reference to
the following aspects described in detail in conjunction with the
accompanying drawings. However, the present disclosure is not
limited to those aspects disclosed below but may be implemented in
various different forms. It should be noted that the present
aspects are merely provided to make a full disclosure and also to
allow those skilled in the art to know the full range of the
disclosure, and therefore, the present disclosure is to be defined
only by the scope of the appended claims. Further, like reference
numerals refer to like or similar elements throughout the
specification. In the drawings, the size and relative size of
layers and regions may be exaggerated for the clarity of the
description.
An element or layer referred to as being "on" another element or
layer may include both a case where it is directly on the another
element or layer and a case where another element and layer is
interposed therebetween. On the contrary, an element referred to as
being "directly on" another element indicates a case where another
element and layer is not interposed therebetween.
Spatially relative terms such as "below", "beneath", "lower",
"above", or "upper" may be used herein to describe a correlation
between one device or constituent element and other devices or
constituent elements as illustrated in the drawings. It will be
understood that spatially relative terms are intended to include a
different direction of device during the use or operation in
addition to its direction illustrated in the drawings. For example,
when a device in the drawing is turned over, the device described
as "below" or "beneath" another device will be placed "above" the
another device. Accordingly, the exemplary terms "below" or
"beneath" may include both directions of above and below. Since the
device may be oriented in another direction, and thus the spatially
relative terms may be interpreted in accordance with the
orientation thereof.
It should be noted that the terms used herein are merely used to
describe the aspects, but not to limit the present disclosure. In
the present specification, unless clearly used otherwise,
expressions in a singular form include a plural form. The term
"comprises" and/or "comprising" used in the specification intend to
express a constituent element, a step, an operation and/or a device
does not exclude the existence or addition of one or more other
constituent elements, steps, operations and/or devices.
FIG. 2 is a cross-sectional view showing a lighting panel using an
organic light-emitting diode according to a first aspect of the
present disclosure.
FIG. 3 is a plan view schematically showing a lighting panel using
an organic light-emitting diode according to the first aspect of
the present disclosure.
FIG. 4 is a view schematically showing a cross-section of a
lighting panel using an organic light-emitting diode according to
the first aspect taken along line I-I' in FIG. 3.
The present disclosure provides a lighting panel using an organic
light-emitting diode made of an organic material instead of an
inorganic light-emitting diode made of an inorganic material.
The organic light-emitting diode made of an organic light-emitting
material has relatively good luminous efficiency of green and red
as compared with the inorganic light-emitting diode. In addition,
since the organic light-emitting diode have the emission peak of
red, green and blue with a relatively wide width as compared with
the inorganic light-emitting diode, the organic light-emitting
diode has an advantage that the color rendering index (CRI) is
improved and light of a light-emitting device is more similar to
the sunlight.
In the following description, the lighting panel of the present
disclosure is described as a flexible lighting panel having
flexibility. However, the present disclosure can be applied to a
general lighting panel that is not bendable as well as to a
flexible lighting panel.
Referring to FIGS. 2 to 4, the lighting panel 100 using an organic
light-emitting diode according to the first aspect of the present
disclosure may include an organic light-emitting diode unit 100a
for emitting planar light and an encapsulation unit 102 for
encapsulating the organic light-emitting diode unit 100a.
At this time, an external light extraction (or outcoupling) layer
145 may be further provided under the organic light-emitting diode
unit 100a to increase the haze. However, the present disclosure is
not limited thereto, and an external light extraction layer may not
be provided.
The external light extraction layer 145 may be formed of scattering
particles of TiO.sub.2 or the like dispersed in a resin and may be
attached to a lower portion of a substrate 110 through an adhesive
layer (not shown).
The organic light-emitting diode unit 100a includes an organic
light-emitting diode provided on the substrate 110. At this point,
an internal light extraction layer 140 may be further provided
between the substrate 110 and the organic light-emitting diode.
However, the present disclosure is not limited thereto, and an
internal light extraction layer may not be provided.
The internal light extraction layer 140 may be formed of scattering
particles of TiO.sub.2, ZrO.sub.2 or the like dispersed in a resin,
but the present disclosure is not limited thereto.
A buffer layer 101 may be further provided on the internal light
extraction layer 140.
At this time, the substrate 110 may include an emission portion EA
that actually emits light and outputs the light to the outside and
contact portions CA1 and CA2 that are electrically connected to the
outside through contact electrodes 127 and 128 to apply a signal to
the emission portion EA.
The contact portions CA1 and CA2 may not be covered by an
encapsulation member of a metal film 170 and/or a protection film
175 and may be electrically connected to the outside through the
contact electrodes 127 and 128. Therefore, the metal film 170
and/or protection film 175 may be attached to an entire surface of
the emission portion EA of the substrate 110 excluding the contact
portions CA1 and CA2. However, the present disclosure is not
limited thereto.
At this time, the contact portions CA1 and CA2 may be located
outside the emission portion EA. FIG. 3 shows that a second contact
portion CA2 including the contact electrode 128 is disposed between
first contact portions CA1 including the contact electrode 127 as
an example, but the present disclosure is not limited thereto.
In addition, FIG. 3 illustrates that the contact portions CA1 and
CA2 are located only at one side of the emission portion EA, but
the present disclosure is not limited thereto. Accordingly, the
contact portions CA1 and CA2 of the present disclosure may be
disposed both at upper and lower sides of the emission portion
EA.
A first electrode 116 and a second electrode 126 may be disposed on
the substrate 110, and an organic light-emitting layer 130 may be
disposed between the first electrode 116 and the second electrode
126, thereby forming the organic light-emitting diode. In the
lighting panel 100 having the above structure, the organic
light-emitting layer 130 emits light by applying currents to the
first electrode 116 and the second electrode 126 of the organic
light-emitting diode, and light is outputted through the emission
portion EA.
The organic light-emitting layer 130 may be a light-emitting layer
that outputs white light. For example, the organic light-emitting
layer 130 may include a blue light-emitting layer, a red
light-emitting layer and a green light-emitting layer or may have a
tandem structure including a blue light-emitting layer and a
yellow-green light-emitting layer. However, the organic
light-emitting layer 130 of the present disclosure is not limited
to the above-described structure, and various structures may be
applied.
Moreover, the organic light-emitting layer 130 of the present
disclosure may further include an electron injection layer and a
hole injection layer for injecting electrons and holes into the
light-emitting layer, respectively, an electron transport layer and
a hole transport layer for transporting the injected electrons and
holes to the light-emitting layer, respectively, and a charge
generation layer for generating charges such as electrons and
holes.
At this time, a first passivation layer 115a, the organic
light-emitting layer 130 and the second electrode 126 are not
formed in the contact portions CA1 and CA2 outside the emission
portion EA, and the contact electrodes 127 and 128 may be exposed
to the outside.
At this time, although not shown in the figures, a second
passivation layer of an organic material and a third passivation
layer of an inorganic material may be formed in the emission
portion EA so as to cover the organic light-emitting layer 130 and
the second electrode 126.
Generally, when a polymer constituting an organic light-emitting
material is combined with moisture, luminescent characteristics are
rapidly deteriorated, and the luminous efficiency of the organic
light-emitting layer 130 is lowered. Particularly, when a part of
the organic light-emitting layer 130 is exposed to the outside, the
moisture is propagated into the lighting panel 100 along the
organic light-emitting layer 130 to thereby lower the luminous
efficiency of the lighting panel 100. Accordingly, in the present
disclosure, the second passivation layer and the third passivation
layer are formed to cover the organic light-emitting layer 130 and
the second electrode 126 of the emission portion EA, and thus
moisture is prevented from permeating through the organic
light-emitting layer 130 of the emission portion EA of the lighting
panel 100 where light is actually emitted and outputted. Therefore,
the yield is improved, the manufacturing costs are reduced, and the
reliability is secured.
As described above, the first electrode 116 including the first
contact electrode 127 and the second contact electrode 128 are
disposed on the substrate 110 of a transparent material. The
substrate 110 may be formed of a rigid material such as glass.
However, by using a material having flexibility such as plastic, it
is possible to manufacture the lighting panel 100 which can be
bent. Moreover, in the present disclosure, by using a plastic
material having flexibility as the substrate 110, it is possible to
perform a process using a roll, thereby manufacturing the lighting
panel 100 quickly.
The first electrode 116 including the first contact electrode 127
and the second contact electrode 128 may be disposed in the
emission portion EA and the first and second contact portions CA1
and CA2 and may be formed of a transparent conductive material
having relatively high conductivity and high work function. For
example, the first electrode 116 including the first contact
electrode 127 and the second contact electrode 128 may be formed of
a tin oxide conductive material such as indium tin oxide (ITO) or a
zinc oxide conductive material such as indium zinc oxide (IZO) or
may be formed of a transparent conductive polymer.
At this time, in the present disclosure, a short reduction pattern
117 is formed in the first electrode 116 for providing each pixel
with currents to reflect a narrow path, and the first passivation
layer 115a covers the short reduction pattern 117 to prevent
occurrence of a short circuit. That is, the short reduction pattern
117 is formed so as to surround the periphery of an emission area
of each pixel, and a resistance is added to each pixel, thereby
limiting the currents flowing to a short-circuit occurrence
region.
The first electrode 116 may extend to the first contact portion CA1
outside the emission portion EA and may constitute the first
contact electrode 127. The second contact electrode 128 may be
disposed in the second contact portion CA2 and may be electrically
insulated from the first electrode 116. Namely, the second contact
electrode 128 may be disposed in the same layer as the first
electrode 116 and may be electrically isolated from the first
electrode 116.
As an example, FIG. 3 shows that the first electrode 116 including
the first contact electrode 127 has a rectangular shape as a whole
and includes an upper center portion, which is removed to form a
recession, and the second contact electrode 128 is disposed in the
recession. However, the present disclosure is not limited
thereto.
An auxiliary electrode 111 may be disposed in the emission portion
EA and the first contact portion CA1 on the substrate 110 and may
be electrically connected to the first electrode 116 and the first
contact electrode 127. Since the first electrode 116 is formed of a
transparent high resistance conductive film, the first electrode
116 has an advantage of light transmission and also has a
disadvantage of very high electrical resistance as compared with an
opaque metal. Therefore, when a large area lighting panel 100 is
manufactured, distribution of currents applied to a large emission
area is not uniform due to the high resistance of the transparent
high resistance conductive film, and this non-uniform current
distribution makes it difficult that the large area lighting panel
100 emits light of uniform brightness.
The auxiliary electrode 111 is arranged in a shape of a mesh with a
thin width, a hexagon, an octagon or a circle all over the emission
portion EA such that uniform currents can be applied to the first
electrode 116 all over the emission portion EA and the large area
lighting panel 100 can emit light of uniform brightness.
FIG. 4 shows that the auxiliary electrode 111 is disposed under the
first electrode 116 including the first contact electrode 127 and
is embedded in the internal light extraction layer 140 and the
buffer layer 101 as an example, but the present disclosure is not
limited thereto. The auxiliary electrode 111 may be embedded only
in one of the internal light extraction layer 140 and the buffer
layer 101. In addition, the auxiliary electrode 111 of the present
disclosure may be embedded up to a thickness of the internal light
extraction layer 140 and/or the buffer layer 101 or may be embedded
up to a part of the thickness of the internal light extraction
layer 140 and/or the buffer layer 101. In the present disclosure,
it is also possible to further form a specific layer of an
inorganic film for embedding the auxiliary electrode 111.
At this time, in FIG. 4, as an example, the auxiliary electrode 111
is embedded with a reversed taper in the internal light extraction
layer 140 and the buffer layer 101, but the present disclosure is
not limited thereto. The auxiliary electrode 111 may be embedded
with a taper of substantially 90 degrees. Here, the reversed taper
means that an upper part of the auxiliary electrode 111 embedded in
the internal light extraction layer 140 and the buffer layer 101
has a wider width than a lower part thereof. Accordingly, when the
auxiliary electrode 111 has a taper of 90 degrees, the width of the
upper part is substantially equal to the width of the lower
part.
The auxiliary electrode 111 according to the present disclosure may
be embedded in the same layer or the lower layer without protruding
above the internal light extraction layer 140 and/or the buffer
layer 101.
When the auxiliary electrode 111 is embedded in the internal light
extraction layer 140 and/or the buffer layer 101, a step is not
formed between the auxiliary electrode 111 and the upper layer, and
it is prevented that the passivation layers (i.e., the first,
second and third passivation layers 115a) and a cathode (i.e., the
second electrode 126) are cracked. As a result, the effect of
improving the reliability of the lighting panel can be
provided.
At this time, the auxiliary electrode 111 disposed in the first
contact portion CA1 is used as a transmission path for the currents
to the first electrode 116 through the first contact electrode 127.
The auxiliary electrode 111 may contact the outside and may serve
as a contact electrode for applying currents from the outside to
the first electrode 116.
The auxiliary electrode 111 may be formed of a conductive metal
such as Al, Au, Cu, Ti, W, Mo or an alloy thereof. The auxiliary
electrode 111 may have a two-layer structure of an upper auxiliary
electrode and a lower auxiliary electrode, but the present
disclosure is not limited thereto. The auxiliary electrode 111 may
be formed of a single layer.
The first passivation layer 115a may be formed in the emission
portion EA of the substrate 110. In FIG. 3, the first passivation
layer 115a is shown as rectangular frame shape having a uniform
width as a whole. In practice, the first passivation layer 115a may
be removed in a light-emitting region and may be formed in a shape
of a mesh so as to cover the auxiliary electrode 111, which is
arranged in a shape of a mesh. However, the present disclosure is
not limited thereto.
The first passivation layer 115a disposed in the emission portion
EA may be formed to cover the auxiliary electrode 111 and the first
electrode 116 thereon. The first passivation layer 115a is not
formed in the light-emitting region where light is actually
emitted.
The first passivation layer 115a may be formed of an inorganic
material such as SiOx or SiNx. However, the first passivation layer
115a may be formed of an organic material such as photo acryl or
may be composed of a plurality of layers of an inorganic material
and an organic material.
In addition, the organic light-emitting layer 130 and the second
electrode 126 may be disposed on the substrate 110 on which the
first electrode 116 and the first passivation layer 115a are
disposed. At this time, the first passivation layer 115a on the
second contact electrode 128 in the emission portion EA may be
partially removed and may have a contact hole 114 exposing the
second contact electrode 128. Accordingly, the second electrode 126
may be electrically connected to the second contact electrode 128
thereunder through the contact hole 114.
As described above, the organic light-emitting layer 130, as a
white light-emitting layer, may include a blue light-emitting
layer, a red light-emitting layer and a green light-emitting layer
or may have a tandem structure including a blue light-emitting
layer and a yellow-green light-emitting layer. In addition, the
organic light-emitting layer 130 may further include an electron
injection layer and a hole injection layer for injecting electrons
and holes into the light-emitting layer, respectively, an electron
transport layer and a hole transport layer for transporting the
injected electrons and holes to the light-emitting layer,
respectively, and a charge generation layer for generating charges
such as electrons and holes.
The second electrode 126 may be formed of a material having
relatively low work function such that electrons are easily
injected to the organic light-emitting layer 130. Specific examples
of a material used as the second electrode 126 may include a metal
such as magnesium, calcium, sodium, titanium, indium, yttrium,
lithium, gadolinium, aluminum, silver, tin and lead or an alloy
thereof.
The first electrode 116, the organic light-emitting layer 130 and
the second electrode 126 of the emission portion EA constitute the
organic light-emitting diode. At this time, the first electrode 116
is an anode of the organic light-emitting diode, and the second
electrode 126 is a cathode of organic light-emitting diode. When
currents are applied to the first electrode 16 and the second
electrode 126, electrons are injected from the second electrode 126
into the organic light-emitting layer 130, and holes are injected
from the first electrode 116 into the organic light-emitting layer
130. After this, excitons are generated in the organic
light-emitting layer 130, and light corresponding to an energy
difference between the LUMO (lowest unoccupied molecular orbital)
and the HOMO (highest occupied molecular orbital) of the
light-emitting layer is emitted to a lower direction (toward the
substrate 110 in the figure) as the excitons decay.
At this time, although not shown in the figures, the second
passivation layer and the third passivation layer may be provided
on the substrate 110 on which the second electrode 126 is
formed.
The second passivation layer according to the first aspect of the
present disclosure, as described above, may be formed to cover the
organic light-emitting layer 130 and the second electrode 126 of
the emission portion EA and may prevent moisture from penetrating
into the organic light-emitting layer 130 of the emission portion
EA.
That is, in the present disclosure, the second passivation layer
and the third passivation layer are formed to cover the organic
light-emitting layer 130 and the second electrode 126 of the
emission portion EA in addition to an adhesive 118 and the
encapsulation member of the metal film 170, and it is possible to
prevent moisture from penetrating into the organic light-emitting
layer 130 of the emission portion EA of the lighting panel 100
where light is actually emitted and outputted.
The second passivation layer may be formed of an organic material
such as photo acryl. In addition, the third passivation layer may
be formed of an inorganic material such as SiOx or SiNx. However,
the present disclosure is not limited thereto.
A predetermined encapsulant may be provided on the third
passivation layer, and an epoxy compound, an acrylate compound, an
acrylic compound, or the like may be used as the encapsulant.
As described above, the first contact electrode 127 extending from
the first electrode 116 is exposed to the outside on the substrate
110 of the first contact portion CAL The second contact electrode
128 electrically connected to the second electrode 126 through the
contact hole 114 is exposed to the outside on the substrate 110 of
the second contact portion CA2. Accordingly, the first contact
electrode 127 and the second contact electrode 128 are electrically
connected to an external power source, so that currents can be
applied to the first electrode 116 and the second electrode 126,
respectively.
An adhesive 118 such as PSA (pressure sensitive adhesive) is
applied on the third passivation layer, the metal film 170 is
disposed thereon, and the metal film 170 is attached to the third
passivation layer, so that the lighting panel 100 can be
encapsulated.
At this time, the adhesive 118 and the encapsulation member of the
metal film 170 can be attached so as to sufficiently cover the
second passivation layer and the third passivation layer.
In addition, a predetermined protection film 175 may be disposed
thereon and attached to an entire surface of the emission portion
EA of the substrate 110 excluding the contact portions CA1 and
CA2.
The adhesive 118 may be a photo-curable adhesive or a thermosetting
adhesive.
Hereinafter, a method of fabricating a lighting panel using an
organic light-emitting diode according to the first aspect of the
present disclosure with reference to the drawings.
FIGS. 5A to 5G are plan views sequentially illustrating a method of
fabricating a lighting panel using an organic light-emitting diode
according to the first aspect of the present disclosure shown in
FIG. 3.
FIGS. 6A to 6G are cross-sectional views sequentially illustrating
a method of fabricating a lighting panel using an organic
light-emitting diode according to the first aspect of the present
disclosure shown in FIG. 4.
FIG. 7 is a view enlarging a part of an emission portion shown in
FIG. 5D.
First, referring to FIG. 5A and FIG. 6A, an internal light
extraction layer 140 is formed on a substantially entire surface of
a substrate 110. However, the present disclosure is not limited
thereto, and an internal light extraction layer may not be
formed.
At this time, the internal light extraction layer 140 may be formed
of scattering particles of TiO.sub.2, ZrO.sub.2, or the like
dispersed in a resin, and the present disclosure is not limited
thereto.
A buffer layer 101 may be further provided on the internal light
extraction layer 140.
At this point, the substrate 110 may include an emission portion
for actually emitting and outputting light to the outside and a
contact portion for electrically connecting with the outside
through a contact electrode and applying signals to the emission
portion.
Next, referring to FIG. 5B and FIG. 6B, the internal light
extraction layer 140 and/or the buffer layer 101 are partially
removed, and a conductive material is deposited and embedded in a
removed part to thereby form a predetermined auxiliary electrode
111.
As described above, the auxiliary electrode 111 according to the
first aspect of the present disclosure is embedded in the internal
light extraction layer 140 and the buffer layer 101 as an example,
and the present disclosure is not limited thereto. The auxiliary
electrode 111 of the present disclosure may be embedded only in the
internal light extraction layer 140 or the buffer layer 101. In
addition, the auxiliary electrode 111 of the present disclosure may
be embedded up to a thickness of the internal light extraction
layer 140 and/or the buffer layer 101 or may be embedded up to a
part of the thickness of the internal light extraction layer 140
and/or the buffer layer 101. Moreover, the present disclosure may
add a specific layer of an inorganic layer to embed the auxiliary
electrode 111.
At this time, FIG. 6B shows that the auxiliary electrode 111 is
embedded in the internal light extraction layer 140 and the buffer
layer 101 so as to have a reversed taper as an example, but the
present disclosure is not limited thereto. The auxiliary electrode
111 may be embedded to have a taper of substantially 90
degrees.
Furthermore, the auxiliary electrode 111 according to the first
aspect of the present disclosure may not protrude above the
embedded layer (i.e., the internal light extraction layer 140
and/or the buffer layer 101) and may be embedded in the same layer
or in the lower layer. Accordingly, the buffer layer 101 where the
auxiliary electrode 111 is embedded can have a planarized surface.
In this case, a step is not formed between the auxiliary electrode
111 and the upper layer, and it is possible to prevent the
passivation layer and the cathode from being cracked due to the
step and taper of the auxiliary electrode of the related art. As a
result, the effect of improving the reliability of the lighting
panel can be provided.
In addition, the auxiliary electrode 111 is arranged in a shape of
a mesh with a thin width, a hexagon, an octagon or a circle all
over the emission portion such that uniform currents can be applied
to the first electrode all over the emission portion and a large
area lighting panel can emit light of uniform brightness.
The auxiliary electrode 111 embedded according to the first aspect
of the present disclosure can be formed by various methods such as
a laser patterning process or a photolithography process, and this
will be described in detail with reference to the following
drawings.
FIGS. 8A to 8C are cross-sectional views specifically illustrating
a method of forming the auxiliary electrode shown in FIG. 6B.
At this time, in the method of forming the auxiliary electrode
shown in FIGS. 8A to 8C, the internal light extraction layer and
the buffer layer are patterned using a laser patterning process,
and the auxiliary electrode is formed using a photolithography
process, as an example.
Referring to FIG. 8A, a laser 150 is irradiated on the substrate
110 where the internal light extraction layer 140 and the buffer
layer 101 are formed, thereby partially removing the internal light
extraction layer 140 and the buffer layer 101.
At this time, the internal light extraction layer 140 and the
buffer layer 101, which are selectively removed, may include an
auxiliary electrode pattern T having a depressed shape, and the
auxiliary electrode pattern T may be provided in a region where the
auxiliary electrode will be formed later.
Here, FIG. 8A shows a case where the internal light extraction
layer 140 and the buffer layer 101 are patterned such that a width
of the auxiliary electrode pattern T is narrowed from the top to
the bottom as an example, but the present disclosure is not limited
thereto.
After this, referring to FIG. 8B, a predetermined photoresist
pattern 160 is formed on the buffer layer 101 excluding the
auxiliary electrode pattern T so as to form the auxiliary
electrode.
Referring to FIG. 8C, a predetermined conductive material is
deposited on a substantially entire surface of the substrate 110
including the inside of the auxiliary electrode pattern T to
thereby form a conductive layer 120.
At this time, the conductive material deposited inside the
auxiliary electrode pattern T constitutes the auxiliary electrode
111.
The conductive material for forming the auxiliary electrode 111 and
the conductive layer 120 may include a metal having good
conductivity such as Al, Au, Cu, Ti, W, Mo, or an alloy
thereof.
Thereafter, the photoresist pattern 160 and the conductive layer
120 on the photoresist pattern 160 are selectively removed through
a lift-off process, thereby forming the auxiliary electrode 111
made of the conductive material inside the internal light
extraction layer 140 and the buffer layer 101, that is, inside the
auxiliary electrode pattern T.
FIGS. 9A and 9B are cross-sectional views specifically illustrating
another method of forming the auxiliary electrode shown in FIG.
6B.
At this time, the method of FIGS. 9A and 9B is substantially the
same as the method of FIGS. 8A to 8C described above except that a
soluble coating process is used to form the auxiliary electrode
instead of the photolithography process.
Referring to FIG. 9A, a predetermined area of the internal light
extraction layer 140 and the buffer layer 101 is removed using the
above-described laser patterning process to thereby form an
auxiliary electrode pattern having a depressed shape.
Thereafter, a liquid-type metal is coated on the substantially
entire surface of the substrate 110, thereby forming a metal layer
111'. At this time, the metal layer 111' may be formed on the
substantially entire surface of the substrate 110 including the
inside of the auxiliary electrode pattern.
Then, a tool such as a blade 155 can be inserted into one direction
from one side to another side of the substrate 110, thereby
removing the metal layer on the substrate 110 excluding the inside
of the auxiliary electrode pattern and forming the predetermined
auxiliary electrode 111.
FIGS. 10A to 10C are cross-sectional views specifically
illustrating another method of forming the auxiliary electrode
shown in FIG. 6B.
At this time, the method of FIGS. 10A to 10C shows a case where the
internal light extraction layer and the buffer layer are patterned
using a photolithography process instead of the laser patterning
process, and at the same time, the auxiliary electrode is formed,
as an example.
Referring to FIG. 10A, a predetermined photoresist pattern 160 is
formed on the substrate 110 on which the internal light extraction
layer 140 and the buffer layer 101 are formed.
At this time, the photoresist pattern 160 may be formed on the
buffer layer 101 excluding the region where the auxiliary electrode
is formed later.
Next, referring to FIG. 10B, the internal light extraction layer
140 and the buffer layer 101 are selectively removed using the
photoresist pattern 160 as a mask, thereby forming an auxiliary
electrode pattern T having a depressed shape inside the internal
light extraction layer 140 and the buffer layer 101.
At this time, FIG. 10B shows a case where the internal light
extraction layer 140 and the buffer layer 101 are patterned such
that a width of the auxiliary electrode pattern T is narrowed from
the top to the bottom as an example, but the present disclosure is
not limited thereto.
Next, referring to FIG. 10C, a predetermined conductive material is
deposited on the substantially entire surface of the substrate
including the inside of the auxiliary electrode pattern T, thereby
forming a conductive layer 111' on the photoresist pattern 160.
At this time, the conductive material deposited inside the
auxiliary electrode pattern T constitutes the auxiliary electrode
111.
The conductive material for forming the auxiliary electrode 111 and
the conductive layer 111' may include a metal having good
conductivity such as Al, Au, Cu, Ti, W, Mo, or an alloy
thereof.
Thereafter, the photoresist pattern 160 and the conductive layer
111' on the photoresist pattern 160 are selectively removed through
a lift-off process, thereby forming the auxiliary electrode 111
made of the conductive material inside the internal light
extraction layer 140 and the buffer layer 101, that is, inside the
auxiliary electrode pattern T.
Then, referring to FIG. 5C and FIG. 6C, a transparent conductive
material such as ITO or IZO is deposited over the substantially
entire surface of the substrate 110 and is etched to thereby form a
first electrode 116 including a first contact electrode 127 and a
second contact electrode 128 in the emission portion and the first
and second contact portions.
At this time, the first electrode 116 may extend into the first
contact portion outside the emission portion to constitute the
first contact electrode, and the second contact electrode 128,
which is electrically insulated from the first electrode 116, may
be formed in a part of the emission portion and the second contact
portion. That is, the second contact electrode 128 is formed in the
same layer as the first electrode 116 and may be separated and
electrically isolated from the first electrode 116.
For example, FIG. 5C shows an example where the first electrode 116
including the first contact electrode 127 has a rectangular shape
as a whole, an upper center part of the first electrode 116 is
removed to form a recession, and the second contact electrode 128
is formed in the recession, but the present disclosure is not
limited thereto.
At this time, a predetermined short reduction pattern 117 may be
formed in the first electrode 116 at the periphery of the inside of
an emission area
In the present disclosure, since the auxiliary electrode 111 is
embedded and formed in the internal light extraction layer 140 and
the buffer layer 101, the first electrode 116 on the auxiliary
electrode 111 is formed without a step.
Referring to FIG. 5D and FIG. 6D, an inorganic material such as
SiNx or SiOx or an organic material such as photo acryl is layered
substantially all over the substrate 110. Then, the inorganic
material or the organic material is etched to thereby form a first
passivation layer 115a on the auxiliary electrode 111 in the
emission portion and simultaneously form a contact hole 114
exposing the second contact electrode 128.
At this time, the first passivation layer 115a is formed on the
first electrode 116 so as to cover the auxiliary electrode 111 and
is not formed in the emission area where light is actually emitted.
However, referring FIG. 5D and FIG. 7, the first passivation layer
115a may be formed to have a mesh shape in the center of the
emission portion so as to cover the auxiliary electrode 111
arranged in a mesh shape. In FIG. 5D, the first passivation layer
115a has a rectangular frame shape having a uniform width as a
whole, and as described above, the first passivation layer 115a may
have a mesh shape in the center of the emission portion so as to
cover the auxiliary electrode 111 arranged in a mesh shape. In
addition, FIG. 5D shows an example in which the first passivation
layer 115a on the first electrode 116 is separated from the first
passivation layer 115a on the second contact electrode 128, but the
present disclosure is not limited thereto.
Here, the first passivation layer 115a may be formed inside the
short reduction pattern 117.
Thereafter, referring to FIGS. 5E and 5F and FIGS. 6E and 6F, an
organic light-emitting layer 130 and a second electrode 126 are
formed of an organic light-emitting material and a metal,
respectively, in the emission portion of the substrate 110.
First, referring to FIG. 5E and FIG. 6E, the organic light-emitting
layer 130 of an organic light-emitting material is formed in the
emission portion of the substrate 110.
At this time, the organic light-emitting layer 130, as a white
light-emitting layer, may include a red light-emitting layer, a
green light-emitting layer and a blue light-emitting layer or may
have a tandem structure including a blue light-emitting layer and a
yellow-green light-emitting layer. In addition, the organic
light-emitting layer 130 may further include an electron injection
layer and a hole injection layer for injecting electrons and holes
into the light-emitting layer, respectively, an electron transport
layer and a hole transport layer for transporting the injected
electrons and holes to the light-emitting layer, respectively, and
a charge generation layer for generating charges such as electrons
and holes.
Next, referring to FIG. 5F and FIG. 6F, the second electrode 126 of
a metal is formed in the emission portion of the substrate 110 so
as to cover the organic light-emitting layer 130.
At this time, the second electrode 126 may be electrically
connected to the second contact electrode 128 thereunder through
the contact hole 114.
The second electrode 126 may be formed of a metal such as
magnesium, calcium, sodium, titanium, indium, yttrium, lithium,
gadolinium, aluminum, silver, tin and lead or an alloy thereof.
The first electrode 116, the organic light-emitting layer 130 and
the second electrode 126 constitute an organic light-emitting
diode.
At this time, since the first passivation layer 115 is disposed on
the auxiliary electrode 111 of the emission portion, the organic
light-emitting layer 130 on the auxiliary electrode 111 does not
directly contact the first electrode 116, and an organic
light-emitting diode is not formed on the auxiliary electrode
111.
Although not shown, a second passivation layer of an organic
material may be formed in the emission portion of the substrate 110
so as to cover the organic light-emitting layer 130 and the second
electrode 126.
At this time, as described above, the second passivation layer may
be formed so as to cover the organic light-emitting layer 130 and
the second electrode 126 of the emission portion and may prevent
moisture from penetrating into the organic light-emitting layer 130
of the emission portion.
The organic light-emitting layer 130, the second electrode 126 and
the second passivation layer may be formed in-line through
roll-manufacturing apparatus, but the present disclosure is not
limited thereto.
Next, a third passivation layer may be formed in the emission
portion of the substrate 110 so as to cover the second passivation
layer.
The third passivation layer may be formed through another
roll-manufacturing apparatus.
The third passivation layer may be formed of an inorganic material
such as SiOx or SiNx. However, the present disclosure is not
limited thereto.
A predetermined encapsulant may be further provided on the third
passivation layer, and the encapsulant may be formed of an epoxy
compound, an acrylate compound or an acrylate compound.
Then, referring to FIG. 5G and FIG. 6G, an adhesive 118 of a
photo-curable adhesive material or a thermosetting adhesive
material is applied on the emission portion of the substrate 110.
In addition, a metal film 170 is disposed thereon, and the metal
film 170 is attached thereto by curing the adhesive 118.
At this time, since the first and second contact portions are not
covered by the encapsulation member of the metal film 170, the
first and second portions may be electrically connected to the
outside through the first and second contact electrodes 127 and
128.
Thereafter, a predetermined protection film 175 may be attached to
a substantially entire surface of the emission portion of the
substrate 110 excluding the contact portions, thereby completing
the lighting panel.
Like this, the first aspect of the present disclosure is
characterized in that the auxiliary electrode is embedded in the
internal light extraction layer and the buffer layer up to the
thickness of the internal light extraction layer and the buffer
layer. In the present disclosure, it is possible to prevent the
first, second and third passivation layers and the second electrode
from being cracked due to the step and taper of the auxiliary
electrode, thereby improving the reliability of the lighting
panel.
However, as described above, the auxiliary electrode of the present
disclosure may be embedded only in the internal light extraction
layer or the buffer layer. In addition, the auxiliary electrode of
the present disclosure may be embedded up to a part of the
thickness of the internal light extraction layer and/or the buffer
layer. Moreover, in the present disclosure, a specific layer of an
inorganic film can be added so as to embed the auxiliary electrode,
and this will be described in detail with reference to the
following second to fourth aspects.
FIG. 11 is a plan view schematically showing a lighting panel using
an organic light-emitting diode according to a second aspect of the
present disclosure.
FIG. 12 is a view schematically showing a cross-section of the
lighting panel using an organic light-emitting diode according to
the second aspect of the present disclosure taken the line II-II'
in FIG. 11.
The lighting panel using an organic light-emitting diode according
to the second aspect of the present disclosure shown in FIG. 11 and
FIG. 12 has substantially the same structure as that of the first
aspect of the present disclosure described above except that the
internal light extraction layer is removed and the auxiliary
electrode is embedded only in the buffer layer.
That is, the lighting panel using an organic light-emitting diode
according to the second aspect of the present disclosure may
include an organic light-emitting diode unit for emitting planar
light and an encapsulation unit for encapsulating the organic
light-emitting diode unit.
At this time, an external light extraction layer may be further
provided under the organic light-emitting diode unit to increase
the haze. However, the present disclosure is not limited thereto,
and an external light extraction layer may not be provided.
The external light extraction layer may be formed of scattering
particles of TiO.sub.2 or the like dispersed in a resin and may be
attached to a lower portion of a substrate through an adhesive
layer.
The organic light-emitting diode unit includes an organic
light-emitting diode provided on the substrate. At this point, in
the second aspect of the present disclosure, an internal light
extraction layer is not provided between the substrate and the
organic light-emitting diode.
Referring to FIG. 11 and FIG. 12, the substrate 210 may include an
emission portion EA that actually emits light and outputs the light
to the outside and contact portions CA1 and CA2 that are
electrically connected to the outside through contact electrodes
227 and 228 to apply a signal to the emission portion EA.
The contact portions CA1 and CA2 may not be covered by an
encapsulation member of a metal film 270 and/or a protection film
275 and may be electrically connected to the outside through the
contact electrodes 227 and 228. Therefore, the metal film 270
and/or protection film 275 may be attached to an entire surface of
the emission portion EA of the substrate 210 excluding the contact
portions CA1 and CA2. However, the present disclosure is not
limited thereto.
At this time, the contact portions CA1 and CA2 may be located
outside the emission portion EA. FIG. 11 shows that a second
contact portion CA2 including the contact electrode 228 is disposed
between first contact portions CA1 including the contact electrode
227 as an example, but the present disclosure is not limited
thereto.
In addition, FIG. 11 illustrates that the contact portions CA1 and
CA2 are located only at one side of the emission portion EA, but
the present disclosure is not limited thereto. Accordingly, the
contact portions CA1 and CA2 of the present disclosure may be
disposed both at upper and lower sides of the emission portion
EA.
A first electrode 216 and a second electrode 226 may be disposed on
the substrate 210, and an organic light-emitting layer 230 may be
disposed between the first electrode 216 and the second electrode
226, thereby forming the organic light-emitting diode. In the
lighting panel 200 having the above structure, the organic
light-emitting layer 230 emits light by applying currents to the
first electrode 216 and the second electrode 226 of the organic
light-emitting diode, and light is outputted through the emission
portion EA.
At this time, a first passivation layer 215a, the organic
light-emitting layer 230 and the second electrode 226 are not
formed in the contact portions CA1 and CA2 outside the emission
portion EA, and the contact electrodes 227 and 228 may be exposed
to the outside.
At this time, although not shown in the figures, a second
passivation layer of an organic material and a third passivation
layer of an inorganic material may be formed in the emission
portion EA so as to cover the organic light-emitting layer 230 and
the second electrode 226.
As described above, the first electrode 216 including the first
contact electrode 227 and the second contact electrode 228 are
disposed on the substrate 210 of a transparent material. The
substrate 210 may be formed of a rigid material such as glass.
However, by using a material having flexibility such as plastic, it
is possible to manufacture the lighting panel 200 which can be
bent. Moreover, in the present disclosure, by using a plastic
material having flexibility as the substrate 210, it is possible to
perform a process using a roll, thereby manufacturing the lighting
panel 200 quickly.
The first electrode 216 including the first contact electrode 227
and the second contact electrode 228 may be disposed in the
emission portion EA and the first and second contact portions CA1
and CA2 and may be formed of a transparent conductive material
having relatively high conductivity and high work function.
At this time, in the present disclosure, a short reduction pattern
217 is formed in the first electrode 216 for providing each pixel
with currents to reflect a narrow path, and the first passivation
layer 215a covers the short reduction pattern 217 to prevent
occurrence of a short circuit. That is, the short reduction pattern
217 is formed so as to surround the periphery of an emission area
of each pixel, and a resistance is added to each pixel, thereby
limiting the currents flowing to a short-circuit occurrence
region.
The first electrode 216 may extend to the first contact portion CA1
outside the emission portion EA and may constitute the first
contact electrode 227. The second contact electrode 228 may be
disposed in the second contact portion CA2 and may be electrically
insulated from the first electrode 216. Namely, the second contact
electrode 228 may be disposed in the same layer as the first
electrode 216 and may be separated and electrically isolated from
the first electrode 216.
As an example, FIG. 11 shows that the first electrode 216 including
the first contact electrode 227 has a rectangular shape as a whole
and includes an upper center portion, which is removed to form a
recession, and the second contact electrode 228 is disposed in the
recession. However, the present disclosure is not limited
thereto.
An auxiliary electrode 211 may be disposed in the emission portion
EA and the first contact portion CA1 on the substrate 210 and may
be electrically connected to the first electrode 216 and the first
contact electrode 227.
Like the first aspect of the present disclosure, the auxiliary
electrode 211 is arranged in a shape of a mesh with a thin width, a
hexagon, an octagon or a circle all over the emission portion EA
such that uniform currents can be applied to the first electrode
216 all over the emission portion EA and the large area lighting
panel 200 can emit light of uniform brightness.
FIG. 12 shows that the auxiliary electrode 211 is disposed under
the first electrode 216 including the first contact electrode 227
and is embedded in the buffer layer 202 as an example, but as
stated above, the present disclosure is not limited thereto. The
auxiliary electrode 211 of the present disclosure may be embedded
up to a thickness of the buffer layer 202 or may be embedded up to
a part of the thickness of the buffer layer 202.
At this time, the buffer layer 202 according to the second aspect
of the present disclosure may be formed of an inorganic film to
embed the auxiliary electrode 211.
At this time, in FIG. 12, as an example, the auxiliary electrode
211 is embedded with a reversed taper in the buffer layer 202, but
the present disclosure is not limited thereto. The auxiliary
electrode 211 may be embedded with a taper of substantially 90
degrees. As described above, the reversed taper means that an upper
part of the auxiliary electrode 211 embedded in the buffer layer
202 has a wider width than a lower part thereof. Accordingly, when
the auxiliary electrode 211 has a taper of 90 degrees, the width of
the upper part is substantially equal to the width of the lower
part.
The auxiliary electrode 211 according to second aspect of the
present disclosure may be embedded in the same layer or the lower
layer without protruding above the buffer layer 202.
Like this, when the auxiliary electrode 211 is embedded in the
buffer layer 202, a step is not formed between the auxiliary
electrode 211 and the upper layer, and it is prevented that the
passivation layers (i.e., the first, second and third passivation
layers 215a) and a cathode (i.e., the second electrode 226) are
cracked due to the step and taper of the related art auxiliary
electrode. As a result, the effect of improving the reliability of
the lighting panel can be provided.
At this time, the auxiliary electrode 211 disposed in the first
contact portion CA1 is used as a transmission path for the currents
to the first electrode 216 through the first contact electrode 227.
The auxiliary electrode 211 may contact the outside and may serve
as a contact electrode for applying currents from the outside to
the first electrode 216.
The auxiliary electrode 211 may be formed of a conductive metal
such as Al, Au, Cu, Ti, W, Mo or an alloy thereof. The auxiliary
electrode 211 may have a two-layer structure of an upper auxiliary
electrode and a lower auxiliary electrode, but the present
disclosure is not limited thereto. The auxiliary electrode 211 may
be formed of a single layer.
The first passivation layer 215a may be formed in the emission
portion EA of the substrate 210. In FIG. 11, the first passivation
layer 215a is shown as rectangular frame shape having a uniform
width as a whole. In practice, the first passivation layer 215a may
be removed in a light-emitting region and may be formed in a shape
of a mesh so as to cover the auxiliary electrode 211, which is
arranged in a shape of a mesh. However, the present disclosure is
not limited thereto.
The first passivation layer 215a disposed in the emission portion
EA may be formed to cover the auxiliary electrode 211 and the first
electrode 216 thereon. The first passivation layer 215a is not
formed in the light-emitting region where light is actually
emitted.
The first passivation layer 215a may be formed of an inorganic
material such as SiOx or SiNx. However, the first passivation layer
215a may be formed of an organic material such as photo acryl or
may be composed of a plurality of layers of an inorganic material
and an organic material.
In addition, the organic light-emitting layer 230 and the second
electrode 226 may be disposed on the substrate 210 on which the
first electrode 216 and the first passivation layer 215a are
disposed. At this time, the first passivation layer 215a on the
second contact electrode 228 in the emission portion EA may be
partially removed and may have a contact hole 214 exposing the
second contact electrode 228. Accordingly, the second electrode 226
may be electrically connected to the second contact electrode 228
thereunder through the contact hole 214.
The second electrode 226 may be formed of a material having
relatively low work function such that electrons are easily
injected to the organic light-emitting layer 230. Specific examples
of a material used as the second electrode 226 may include a metal
such as magnesium, calcium, sodium, titanium, indium, yttrium,
lithium, gadolinium, aluminum, silver, tin and lead or an alloy
thereof.
The first electrode 216, the organic light-emitting layer 230 and
the second electrode 226 of the emission portion EA constitute the
organic light-emitting diode.
At this time, although not shown in the figures, the second
passivation layer and the third passivation layer may be provided
on the substrate 210 on which the second electrode 226 is
formed.
The second passivation layer according to the second aspect of the
present disclosure, as described above, may be formed to cover the
organic light-emitting layer 230 and the second electrode 226 of
the emission portion EA and may prevent moisture from penetrating
into the organic light-emitting layer 230 of the emission portion
EA.
That is, in the present disclosure, the second passivation layer
and the third passivation layer are formed to cover the organic
light-emitting layer 230 and the second electrode 226 of the
emission portion EA in addition to an adhesive 218 and the
encapsulation member of the metal film 270, and it is possible to
prevent moisture from penetrating into the organic light-emitting
layer 230 of the emission portion EA of the lighting panel 200
where light is actually emitted and outputted.
The second passivation layer may be formed of an organic material
such as photo acryl. In addition, the third passivation layer may
be formed of an inorganic material such as SiOx or SiNx. However,
the present disclosure is not limited thereto.
A predetermined encapsulant may be provided on the third
passivation layer, and an epoxy compound, an acrylate compound, an
acrylic compound, or the like may be used as the encapsulant.
As described above, the first contact electrode 227 extending from
the first electrode 216 is exposed to the outside on the substrate
210 of the first contact portion CAL The second contact electrode
228 electrically connected to the second electrode 226 through the
contact hole 214 is exposed to the outside on the substrate 210 of
the second contact portion CA2. Accordingly, the first contact
electrode 227 and the second contact electrode 228 are electrically
connected to an external power source, so that currents can be
applied to the first electrode 216 and the second electrode 226,
respectively.
An adhesive 218 such as PSA (pressure sensitive adhesive) is
applied on the third passivation layer, the metal film 270 is
disposed thereon, and the metal film 270 is attached to the third
passivation layer, so that the lighting panel 200 can be
encapsulated.
At this time, the adhesive 218 and the encapsulation member of the
metal film 270 can be attached so as to sufficiently cover the
second passivation layer and the third passivation layer.
In addition, a predetermined protection film 275 may be disposed
thereon and attached to an entire surface of the emission portion
EA of the substrate 210 excluding the contact portions CA1 and
CA2.
The adhesive 218 may be a photo-curable adhesive or a thermosetting
adhesive.
FIG. 13 is a cross-sectional view schematically showing a lighting
panel using an organic light-emitting diode according to a third
aspect of the present disclosure.
At this time, the lighting panel using an organic light-emitting
diode according to the third aspect of the present disclosure shown
in FIG. 13 has substantially the same structure as those of the
first and second aspects of the present disclosure described above
except that the auxiliary electrode is embedded up to a part of a
thickness of the internal light extraction layer and/or the buffer
layer.
That is, the lighting panel using an organic light-emitting diode
according to the third aspect of the present disclosure may include
an organic light-emitting diode unit for emitting planar light and
an encapsulation unit for encapsulating the organic light-emitting
diode unit.
At this time, an external light extraction layer may be further
provided under the organic light-emitting diode unit to increase
the haze. However, the present disclosure is not limited thereto,
and an external light extraction layer may not be provided.
The external light extraction layer may be formed of scattering
particles of TiO.sub.2 or the like dispersed in a resin and may be
attached to a lower portion of a substrate through an adhesive
layer.
The organic light-emitting diode unit includes an organic
light-emitting diode provided on the substrate. At this point,
referring to FIG. 13, an internal light extraction layer 340 may be
further provided between a substrate 310 and the organic
light-emitting diode. However, the present disclosure is not
limited thereto, and an internal light extraction layer may not be
provided.
The internal light extraction layer 340 may be formed of scattering
particles of TiO.sub.2, ZrO.sub.2 or the like dispersed in a resin,
but the present disclosure is not limited thereto.
A buffer layer 301 may be further provided on the internal light
extraction layer 340.
At this time, the substrate 310 may include an emission portion EA
that actually emits light and outputs the light to the outside and
contact portions CA1 and CA2 that are electrically connected to the
outside through contact electrodes 327 and 328 to apply a signal to
the emission portion EA.
The contact portions CA1 and CA2 may not be covered by an
encapsulation member of a metal film 370 and/or a protection film
375 and may be electrically connected to the outside through the
contact electrodes 327 and 328. Therefore, the metal film 370
and/or protection film 375 may be attached to an entire surface of
the emission portion EA of the substrate 310 excluding the contact
portions CA1 and CA2. However, the present disclosure is not
limited thereto.
A first electrode 316 and a second electrode 326 may be disposed on
the substrate 310, and an organic light-emitting layer 330 may be
disposed between the first electrode 316 and the second electrode
326, thereby forming the organic light-emitting diode. In the
lighting panel 300 having the above structure, the organic
light-emitting layer 330 emits light by applying currents to the
first electrode 316 and the second electrode 326 of the organic
light-emitting diode, and light is outputted through the emission
portion EA.
At this time, a first passivation layer 315a, the organic
light-emitting layer 330 and the second electrode 326 are not
formed in the contact portions CA1 and CA2 outside the emission
portion EA, and the contact electrodes 327 and 328 may be exposed
to the outside.
At this time, although not shown in the figures, a second
passivation layer of an organic material and a third passivation
layer of an inorganic material may be formed in the emission
portion EA so as to cover the organic light-emitting layer 330 and
the second electrode 326.
As described above, the first electrode 316 including the first
contact electrode 327 and the second contact electrode 328 are
disposed on the substrate 310 of a transparent material. The
substrate 310 may be formed of a rigid material such as glass.
However, by using a material having flexibility such as plastic, it
is possible to manufacture the lighting panel 300 which can be
bent. Moreover, in the present disclosure, by using a plastic
material having flexibility as the substrate 310, it is possible to
perform a process using a roll, thereby manufacturing the lighting
panel 300 quickly.
The first electrode 316 including the first contact electrode 327
and the second contact electrode 328 may be disposed in the
emission portion EA and the first and second contact portions CA1
and CA2 and may be formed of a transparent conductive material
having relatively high conductivity and high work function.
At this time, in the present disclosure, a short reduction pattern
317 is formed in the first electrode 316 for providing each pixel
with currents to reflect a narrow path, and the first passivation
layer 315a covers the short reduction pattern 317 to prevent
occurrence of a short circuit. That is, the short reduction pattern
317 is formed so as to surround the periphery of an emission area
of each pixel, and a resistance is added to each pixel, thereby
limiting the currents flowing to a short-circuit occurrence
region.
The first electrode 316 may extend to the first contact portion CA1
outside the emission portion EA and may constitute the first
contact electrode 327. The second contact electrode 328 may be
disposed in the second contact portion CA2 and may be electrically
insulated from the first electrode 316. Namely, the second contact
electrode 328 may be disposed in the same layer as the first
electrode 316 and may be separated and electrically isolated from
the first electrode 316.
An auxiliary electrode 311 may be disposed in the emission portion
EA and the first contact portion CA1 on the substrate 310 and may
be electrically connected to the first electrode 316 and the first
contact electrode 327.
Like the first and second aspects of the present disclosure
described above, the auxiliary electrode 311 is arranged in a shape
of a mesh with a thin width, a hexagon, an octagon or a circle all
over the emission portion EA such that uniform currents can be
applied to the first electrode 316 all over the emission portion EA
and the large area lighting panel 300 can emit light of uniform
brightness.
FIG. 13 shows that the auxiliary electrode 311 is disposed under
the first electrode 316 including the first contact electrode 327
and is embedded in the internal light extraction layer 340 and the
buffer layer 301 up to a part of a thickness of the internal light
extraction layer 340 as an example, but as stated above, the
present disclosure is not limited thereto. The auxiliary electrode
311 of the present disclosure may be embedded up to a part of a
thickness of the buffer layer 301.
Like this, when the auxiliary electrode 311 is embedded up to the
part of the thickness of the internal light extraction layer 340 or
the buffer layer 301, there are effects that the tact time for the
laser patterning process is reduced and it is possible to prevent
yellowing of a glass substrate 310 or damages to a polyimide
substrate 310 caused when a surface of the glass or polyimide
substrate 310 is exposed.
At this time, in FIG. 13, as an example, the auxiliary electrode
311 is embedded with a reversed taper in the internal light
extraction layer 340 and the buffer layer 301, but the present
disclosure is not limited thereto. The auxiliary electrode 311 may
be embedded with a taper of substantially 90 degrees.
The auxiliary electrode 311 according to third aspect of the
present disclosure may be embedded in the internal light extraction
layer 340 and the buffer layer 301 without protruding above the
buffer layer 301.
Like this, when the auxiliary electrode 311 is embedded in the
internal light extraction layer 340 and the buffer layer 301, a
step is not formed between the auxiliary electrode 311 and the
upper layer, and it is prevented that the first passivation layer
315a to the third passivation layer and the second electrode 326
are cracked due to the step and taper of the related art auxiliary
electrode. As a result, the effect of improving the reliability of
the lighting panel can be provided.
At this time, the auxiliary electrode 311 disposed in the first
contact portion CA1 is used as a transmission path for the currents
to the first electrode 316 through the first contact electrode 327.
The auxiliary electrode 311 may contact the outside and may serve
as a contact electrode for applying currents from the outside to
the first electrode 316.
The auxiliary electrode 311 may be formed of a conductive metal
such as Al, Au, Cu, Ti, W, Mo or an alloy thereof. The auxiliary
electrode 311 may have a two-layer structure of an upper auxiliary
electrode and a lower auxiliary electrode, but the present
disclosure is not limited thereto. The auxiliary electrode 311 may
be formed of a single layer.
The first passivation layer 315a may be formed in the emission
portion EA of the substrate 310. Like the first and second aspects
of the present disclosure described above, the first passivation
layer 315a may be removed in a light-emitting region and may be
formed in a shape of a mesh so as to cover the auxiliary electrode
311, which is arranged in a shape of a mesh. However, the present
disclosure is not limited thereto.
The first passivation layer 315a disposed in the emission portion
EA may be formed to cover the auxiliary electrode 311 and the first
electrode 316 thereon. The first passivation layer 315a is not
formed in the light-emitting region where light is actually
emitted.
The first passivation layer 315a may be formed of an inorganic
material such as SiOx or SiNx. However, the first passivation layer
315a may be formed of an organic material such as photo acryl or
may be composed of a plurality of layers of an inorganic material
and an organic material.
In addition, the organic light-emitting layer 330 and the second
electrode 326 may be disposed on the substrate 310 on which the
first electrode 316 and the first passivation layer 315a are
disposed. At this time, the first passivation layer 315a on the
second contact electrode 328 in the emission portion EA may be
partially removed and may have a contact hole 314 exposing the
second contact electrode 328. Accordingly, the second electrode 326
may be electrically connected to the second contact electrode 328
thereunder through the contact hole 314.
The second electrode 326 may be formed of a material having
relatively low work function such that electrons are easily
injected to the organic light-emitting layer 330. Specific examples
of a material used as the second electrode 326 may include a metal
such as magnesium, calcium, sodium, titanium, indium, yttrium,
lithium, gadolinium, aluminum, silver, tin and lead or an alloy
thereof.
At this time, although not shown in the figures, the second
passivation layer and the third passivation layer may be provided
on the substrate 310 on which the second electrode 326 is
formed.
The second passivation layer according to the third aspect of the
present disclosure, as described above, may be formed to cover the
organic light-emitting layer 330 and the second electrode 326 of
the emission portion EA and may prevent moisture from penetrating
into the organic light-emitting layer 330 of the emission portion
EA.
The second passivation layer may be formed of an organic material
such as photo acryl. In addition, the third passivation layer may
be formed of an inorganic material such as SiOx or SiNx. However,
the present disclosure is not limited thereto.
A predetermined encapsulant may be provided on the third
passivation layer, and an epoxy compound, an acrylate compound, an
acrylic compound, or the like may be used as the encapsulant.
An adhesive 318 such as PSA (pressure sensitive adhesive) is
applied on the third passivation layer, the metal film 370 is
disposed thereon, and the metal film 370 is attached to the third
passivation layer, so that the lighting panel 300 can be
encapsulated.
At this time, the adhesive 318 and the encapsulation member of the
metal film 370 can be attached so as to sufficiently cover the
second passivation layer and the third passivation layer.
In addition, a predetermined protection film 375 may be disposed
thereon and attached to an entire surface of the emission portion
EA of the substrate 310 excluding the contact portions CA1 and
CA2.
The adhesive 318 may be a photo-curable adhesive or a thermosetting
adhesive.
FIG. 14 is a cross-sectional view schematically showing a lighting
panel using an organic light-emitting diode according to a fourth
aspect of the present disclosure.
At this time, the lighting panel using an organic light-emitting
diode according to the fourth aspect of the present disclosure
shown in FIG. 14 has substantially the same structure as those of
the first, second and third aspects of the present disclosure
described above except that the auxiliary electrode is embedded up
to a part of a thickness of the buffer layer and a portion
corresponding to the rest of the thickness of the buffer layer is
filled with the first electrode.
That is, the lighting panel using an organic light-emitting diode
according to the fourth aspect of the present disclosure may
include an organic light-emitting diode unit for emitting planar
light and an encapsulation unit for encapsulating the organic
light-emitting diode unit.
At this time, an external light extraction layer may be further
provided under the organic light-emitting diode unit to increase
the haze. However, the present disclosure is not limited thereto,
and an external light extraction layer may not be provided.
The external light extraction layer may be formed of scattering
particles of TiO.sub.2 or the like dispersed in a resin and may be
attached to a lower portion of a substrate through an adhesive
layer.
The organic light-emitting diode unit includes an organic
light-emitting diode provided on the substrate. At this point,
referring to FIG. 14, an internal light extraction layer 440 may be
further provided between a substrate 410 and the organic
light-emitting diode. However, the present disclosure is not
limited thereto, and an internal light extraction layer may not be
provided.
The internal light extraction layer 440 may be formed of scattering
particles of TiO.sub.2, ZrO.sub.2 or the like dispersed in a resin,
but the present disclosure is not limited thereto.
A buffer layer 401 may be further provided on the internal light
extraction layer 440.
At this time, the substrate 410 may include an emission portion EA
that actually emits light and outputs the light to the outside and
contact portions CA1 and CA2 that are electrically connected to the
outside through contact electrodes 427 and 428 to apply a signal to
the emission portion EA.
The contact portions CA1 and CA2 may not be covered by an
encapsulation member of a metal film 470 and/or a protection film
475 and may be electrically connected to the outside through the
contact electrodes 427 and 428. Therefore, the metal film 470
and/or protection film 475 may be attached to an entire surface of
the emission portion EA of the substrate 410 excluding the contact
portions CA1 and CA2. However, the present disclosure is not
limited thereto.
A first electrode 416 and a second electrode 426 may be disposed on
the substrate 410, and an organic light-emitting layer 430 may be
disposed between the first electrode 416 and the second electrode
426, thereby forming the organic light-emitting diode. In the
lighting panel 400 having the above structure, the organic
light-emitting layer 430 emits light by applying currents to the
first electrode 416 and the second electrode 426 of the organic
light-emitting diode, and light is outputted through the emission
portion EA.
At this time, a first passivation layer 415a, the organic
light-emitting layer 430 and the second electrode 426 are not
formed in the contact portions CA1 and CA2 outside the emission
portion EA, and the contact electrodes 427 and 428 may be exposed
to the outside.
At this time, although not shown in the figures, a second
passivation layer of an organic material and a third passivation
layer of an inorganic material may be formed in the emission
portion EA so as to cover the organic light-emitting layer 430 and
the second electrode 426.
As described above, the first electrode 416 including the first
contact electrode 427 and the second contact electrode 428 are
disposed on the substrate 410 of a transparent material. The
substrate 410 may be formed of a rigid material such as glass.
However, by using a material having flexibility such as plastic, it
is possible to manufacture the lighting panel 300 which can be
bent. Moreover, in the present disclosure, by using a plastic
material having flexibility as the substrate 410, it is possible to
perform a process using a roll, thereby manufacturing the lighting
panel 400 quickly.
The first electrode 416 including the first contact electrode 427
and the second contact electrode 428 may be disposed in the
emission portion EA and the first and second contact portions CA1
and CA2 and may be formed of a transparent conductive material
having relatively high conductivity and high work function.
At this time, in the present disclosure, a short reduction pattern
417 is formed in the first electrode 416 for providing each pixel
with currents to reflect a narrow path, and the first passivation
layer 415a covers the short reduction pattern 417 to prevent
occurrence of a short circuit. That is, the short reduction pattern
417 is formed so as to surround the periphery of an emission area
of each pixel, and a resistance is added to each pixel, thereby
limiting the currents flowing to a short-circuit occurrence
region.
The first electrode 416 may extend to the first contact portion CA1
outside the emission portion EA and may constitute the first
contact electrode 427. The second contact electrode 428 may be
disposed in the second contact portion CA2 and may be electrically
insulated from the first electrode 416. Namely, the second contact
electrode 428 may be disposed in the same layer as the first
electrode 416 and may be separated and electrically isolated from
the first electrode 416.
An auxiliary electrode 411 may be disposed in the emission portion
EA and the first contact portion CA1 on the substrate 410 and may
be electrically connected to the first electrode 416 and the first
contact electrode 427.
Like the first, second and third aspects of the present disclosure
described above, the auxiliary electrode 411 is arranged in a shape
of a mesh with a thin width, a hexagon, an octagon or a circle all
over the emission portion EA such that uniform currents can be
applied to the first electrode 416 all over the emission portion EA
and the large area lighting panel 400 can emit light of uniform
brightness.
FIG. 14 shows that the auxiliary electrode 411 is disposed under
the first electrode 416 including the first contact electrode 427
and is embedded in the internal light extraction layer 440 and the
buffer layer 401 up to a total thickness of the internal light
extraction layer 440 and a part of a thickness of the buffer layer
401 as an example, but as stated above, the present disclosure is
not limited thereto.
At this time, a portion corresponding to the rest of the thickness
of the auxiliary electrode 411 may be filled with the first
electrode 416.
Moreover, in FIG. 14, as an example, the auxiliary electrode 411 is
embedded with a reversed taper in the internal light extraction
layer 440 and the buffer layer 401, but the present disclosure is
not limited thereto. The auxiliary electrode 411 may be embedded
with a taper of substantially 90 degrees.
Like this, when the auxiliary electrode 411 is embedded in the
internal light extraction layer 440 and the buffer layer 401, a
step is not formed between the auxiliary electrode 411 and the
upper layer, and it is prevented that the first passivation layer
415a to the third passivation layer and the second electrode 426
are cracked due to the step and taper of the related art auxiliary
electrode. As a result, the effect of improving the reliability of
the lighting panel can be provided.
At this time, the auxiliary electrode 411 disposed in the first
contact portion CA1 is used as a transmission path for the currents
to the first electrode 416 through the first contact electrode 427.
The auxiliary electrode 411 may contact the outside and may serve
as a contact electrode for applying currents from the outside to
the first electrode 416.
The auxiliary electrode 411 may be formed of a conductive metal
such as Al, Au, Cu, Ti, W, Mo or an alloy thereof. The auxiliary
electrode 411 may have a two-layer structure of an upper auxiliary
electrode and a lower auxiliary electrode, but the present
disclosure is not limited thereto. The auxiliary electrode 411 may
be formed of a single layer.
The first passivation layer 415a may be formed in the emission
portion EA of the substrate 410. Like the first and second aspects
of the present disclosure described above, the first passivation
layer 415a may be removed in a light-emitting region and may be
formed in a shape of a mesh so as to cover the auxiliary electrode
411, which is arranged in a shape of a mesh. However, the present
disclosure is not limited thereto.
The first passivation layer 415a disposed in the emission portion
EA may be formed to cover the auxiliary electrode 411 and the first
electrode 416 thereon. The first passivation layer 415a is not
formed in the light-emitting region where light is actually
emitted.
The first passivation layer 415a may be formed of an inorganic
material such as SiOx or SiNx. However, the first passivation layer
415a may be formed of an organic material such as photo acryl or
may be composed of a plurality of layers of an inorganic material
and an organic material.
In addition, the organic light-emitting layer 430 and the second
electrode 426 may be disposed on the substrate 410 on which the
first electrode 416 and the first passivation layer 415a are
disposed. At this time, the first passivation layer 415a on the
second contact electrode 428 in the emission portion EA may be
partially removed and may have a contact hole 414 exposing the
second contact electrode 428. Accordingly, the second electrode 426
may be electrically connected to the second contact electrode 428
thereunder through the contact hole 414.
The second electrode 426 may be formed of a material having
relatively low work function such that electrons are easily
injected to the organic light-emitting layer 430. Specific examples
of a material used as the second electrode 426 may include a metal
such as magnesium, calcium, sodium, titanium, indium, yttrium,
lithium, gadolinium, aluminum, silver, tin and lead or an alloy
thereof.
At this time, although not shown in the figures, the second
passivation layer and the third passivation layer may be provided
on the substrate 410 on which the second electrode 426 is
formed.
The second passivation layer according to the fourth aspect of the
present disclosure, as described above, may be formed to cover the
organic light-emitting layer 430 and the second electrode 426 of
the emission portion EA and may prevent moisture from penetrating
into the organic light-emitting layer 430 of the emission portion
EA.
The second passivation layer may be formed of an organic material
such as photo acryl. In addition, the third passivation layer may
be formed of an inorganic material such as SiOx or SiNx. However,
the present disclosure is not limited thereto.
A predetermined encapsulant may be provided on the third
passivation layer, and an epoxy compound, an acrylate compound, an
acrylic compound, or the like may be used as the encapsulant.
An adhesive 418 such as PSA (pressure sensitive adhesive) is
applied on the third passivation layer, the metal film 470 is
disposed thereon, and the metal film 470 is attached to the third
passivation layer, so that the lighting panel 400 can be
encapsulated.
At this time, the adhesive 418 and the encapsulation member of the
metal film 470 can be attached so as to sufficiently cover the
second passivation layer and the third passivation layer.
In addition, a predetermined protection film 475 may be disposed
thereon and attached to an entire surface of the emission portion
EA of the substrate 410 excluding the contact portions CA1 and
CA2.
The adhesive 418 may be a photo-curable adhesive or a thermosetting
adhesive.
The present disclosure is not limited to the above first to fourth
aspects. In the present disclosure, the structure on the auxiliary
electrode may not be affected by a step formed due to the auxiliary
electrode through embedding the auxiliary electrode in the buffer
layer and/or the internal light extraction layer. That is, the
embedding of the auxiliary electrode may decrease the size of the
step, so that it is prevented that the passivation layers (i.e.,
the first, second and third passivation layers) and a cathode
(i.e., the second electrode) are cracked due to a step and taper of
the auxiliary electrode, thereby improving the reliability of the
lighting panel. In addition, the embedding of the auxiliary
electrode may cause the step to disappear, i.e., the first
electrode has a planarized surface, so that it is prevented that
the passivation layers (i.e., the first, second and third
passivation layers) and a cathode (i.e., the second electrode) are
cracked due to a step and taper of the auxiliary electrode, thereby
improving the reliability of the lighting panel.
In some aspects of the present disclosure, the auxiliary electrode
may be embedded up to a thickness of a buffer layer or be embedded
up to a part of the thickness of the buffer layer, when the
lighting panel includes the buffer layer but the inner light
extraction layer. Moreover, the auxiliary electrode may be embedded
up to a thickness of a buffer layer or be embedded up to a part of
the thickness of the buffer layer, when the lighting panel includes
the buffer layer and the inner light extraction layer. That is,
even the inner light extraction layer is provided, the auxiliary
electrode may only be provided in the buffer layer. Here, the
auxiliary electrode may be embedded up to a thickness of a buffer
layer refers to the thickness of the auxiliary electrode is similar
as that of the buffer layer. The auxiliary electrode may be
embedded up to a part of the thickness of the buffer layer refers
to the thickness of the auxiliary electrode is less than that of
the buffer layer, and an upper surface of the auxiliary electrode
is flush with an upper surface of the buffer layer, an lower
surface of the auxiliary electrode is flush with an lower surface
of the buffer layer, or both of an upper surface and a lower
surface of the auxiliary electrode are inside the buffer layer. In
addition, in order to render the first electrode has a planarized
surface, for example, an upper surface of the auxiliary electrode
may be flush with an upper surface of the buffer layer, or a
portion corresponding to a rest of the thickness of the buffer
layer other than the part is filled with the first electrode.
In some aspects of the present disclosure, the auxiliary electrode
may be embedded up to a thickness of the buffer layer, and is
further embedded up to a thickness of the inner light extraction
layer or a part of the thickness of the inner light extraction
layer, when the lighting panel includes the buffer layer and the
inner light extraction layer. In this case, an upper surface of the
auxiliary electrode is flush with an upper surface of the buffer
layer such that the first electrode has a planarized surface.
In some aspects of the present disclosure, the auxiliary electrode
is embedded up to a part of a thickness of the buffer layer, and is
further embedded up to a thickness of the inner light extraction
layer or a part of the thickness of the inner light extraction
layer, when the lighting panel includes the buffer layer and the
inner light extraction layer. That is, an upper surface of the
buffer layer is provided inside the buffer layer and a lower
surface of the buffer layer is flush with a lower surface of the
buffer layer, or both of an upper surface and a lower surface of
the auxiliary electrode are inside of the buffer layer and the
inner light extraction layer. In this case, a portion corresponding
to a rest of the thickness of the buffer layer other than the part
is filled with the first electrode such that the first electrode
has a planarized surface.
In some aspects of the present disclosure, there is provided a
lighting panel using an organic light-emitting diode, comprising: a
material layer on a substrate; an auxiliary electrode embedded in
the material layer; a first electrode on the material layer and
electrically connected to the auxiliary electrode; an organic
light-emitting layer and a second electrode in an emission portion
where the first electrode is provided; and an encapsulation member
in the emission portion of the substrate. Here, an upper surface of
the material layer may be flush with an upper surface of the
auxiliary electrode such that the first electrode has a planarized
surface. In addition, the position of the first electrode in
contact with the auxiliary electrode may be lower than an upper
surface of the material layer. That is, the first electrode is
filled on the auxiliary electrode such that the first electrode has
a planarized surface. The material layer may include one or more
layers of organic material and/or inorganic material. The one or
more layers may include a buffer layer and/or an inner light
extraction layer, and may further include other layers. The present
disclosure is not limited thereto, the one or more layers may be
other material layers in which a buffer layer and/or an inner light
extraction layer are not included.
In some aspects of the present disclosure, there is provided a
lighting module comprising the lighting panel according to any
aspects of the present disclosure. Here, the lighting module is a
semi-finished product that constitutes the final lighting device or
lighting system.
In some aspects of the present disclosure, there is provided a
lighting device comprising at least one of the lighting panel and
the lighting module according to aspects of the present disclosure.
Here, the lighting device may be a desk lamp, a wall lamp, a
pendant lamp, a floor lamp, a street lamp, a portable lamp, a
ceiling lamp, or a car lamp.
In some aspects of the present disclosure, there is provided a
lighting system comprising at least one of the lighting panel, the
lighting module and the lighting device according to aspects of the
present disclosure. Here, the lighting system may further include a
controlling device to control the lighting panel, the lighting
module or the lighting device.
It will be apparent to those skilled in the art that various
modifications and variations can be made in a device of the present
disclosure without departing from the sprit or scope of the
aspects. Thus, it is intended that the present disclosure covers
the modifications and variations of this disclosure provided they
come within the scope of the appended claims and their
equivalents.
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